20205240140 has 96 divisors (see below), whose sum is σ = 44653400064. Its totient is φ = 7670465280.

The previous prime is 20205240079. The next prime is 20205240149. The reversal of 20205240140 is 4104250202.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (20205240149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6831542 + ... + 6834498.

It is an arithmetic number, because the mean of its divisors is an integer number (465139584).

Almost surely, 2^20205240140 is an apocalyptic number.

20205240140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20205240140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22326700032).

20205240140 is an abundant number, since it is smaller than the sum of its proper divisors (24448159924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20205240140 is a wasteful number, since it uses less digits than its factorization.

20205240140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3207 (or 3205 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

Adding to 20205240140 its reverse (4104250202), we get a palindrome (24309490342).

The spelling of 20205240140 in words is "twenty billion, two hundred five million, two hundred forty thousand, one hundred forty".